Method and apparatus for irradiating materials



July 20, 1937. L.- J. BUTTOLPH METHOD AND APPARATUS FOR IRRADIA'I'INGMATERIAL Filed May 27, 1932 2 Sheets-Sheet l INVENTOR BY ya 1% ATTORNEYJuly 20, 1937. L. J. BUTTOLPH 2,087,751

' METHOD AND APPARATUS FOR IRRADIATING MATERIALS 2 Sheets-Sheet 2 FiledMay 27, 1932 HEALTH BRAND INVENTOR A'ITORNEY Patented July 20,. 1937UNITED STATES PATENT g-OF FICE METHOD AND APPARATUS FOR IRRADIAT- IN GMATERIALS Leroy J. Buttolph, Grantwood, N. J., assignor to GeneralElectric Vapor Lamp Company, Hoboken, N. J., a corporation of New JerseyApplication Main, 1932, Serial No. 614,018

9 Claims.

The present invention relates to the art of stuilization by ultravioletirradiation, and in partic- -ular to the irradiation of containers torender them sterile. The invention consists in the new and novelapparatus, and in the novel method, as hereinafter set forth andclaimed.

A particular object of my invention is to pro-' another object of myinvention is to provide apparatus which will attract favorable attentionthereto. Still other objects and advantages of my invention will appearfrom the following detailed specification, or from an inspection of theaccompanying drawings.

While it has long been known that ultraviolet irradiation could be usedto kill bacteria, this method of sterilization has not heretofore beenpractical for containers, such as drinking glasses or other relativelydeep, vessels, where both the entire inside and a portion of' theoutside are necessarily irradiated, due to the manipulation required toproduce the desired result from a single artificial source ofultraviolet rays. I have now discovered that by combining an ultravioletgenerator with a reflector of novel shape the desired sterilization,both inside and outside the containers, may be easily accomplished,provided the containers are maintained in a controlled relation to saidgenerator and reflector .for a reasonable period of time. During thisirradiation the containers .are preferably empty, although in some casesit is desirable to fill them with a liquid which is either permeable tothe ultraviolet radiations or which is rendered bactericidal by theirradiation, so'that in any case the entire interior of the container isrendered sterile. I have furthermore found that by means of a novelapparatus of my invention the desired result may be easily accomplishedfor a succession of containers, fed to said apparatus as occasion maydemand, the irradiated containers being taken therefrom in' the samesequence in which they were introduced. My novel apparatus furthermorehas considerable advertising value, inasmuch as that some of the raysfrom the ultraviolet generator are visible through the containers beingto protect the eyes of observers from the injurious far ultravioletrays.

For the purpose of illustration I have shown several views of anapparatus embodying my T invention in the accompanying drawings, inwhich Fig. 1 is a plan view of a sterilizer for drinking glasses, with aportion thereof cut away to the line ll of Fig. 2,

Fig. 2 is an elevational view of the same apparatus,

Fig. 3 is a sectional view of the same apparatus, taken on the line 33of Fig. 1, r

Fig. 4 is a plan view of a portion of the base showing in detail themeans to prevent reverse movement'of the empty containers, and Fig. 5 isa plan view of another portion of the base showing an optionalarrangement for producing positive rotation of the empty containers;

' As shown in these drawings my novel sterilizer has a base plate I ofcast aluminum, or any other suitable material, in the upper surface ofwhich there is an endless channel 2. The major portion of said channelconsists of two parallel legs, symmetrically located with respect to thecenter line of said base, these legs being connected by circularsections at each end. The outer wall of said channel is undercutthroughout its length. In this channel there are a number of holders 3of bakelite, aluminum or other suitable material,

for the empty containers, such as the drinking glasses 4, which are tobe sterilized. These holders may, of course, be minimized in size and/ormade of fused silica or an ultraviolet transmitting glass when largerportions of the exterior of the glasses 4 are to be sterilized. Saidholders each-have a circular flange 5 on the bottom thereof which fitsinto the undercut portion of said channel. A metal plate 6 ofsuitable-shape isaffixed to the top of .the base plate I with its edgesoverlapping the inner wall of said channel 2, whereby said holders 3 arelocked into said channel, but are free to slide or rotate therein.

A trough-like reflecting hood I is mounted on the base plate I, saidhood being symmetrically disposed with'respect to the two parallel legsof the channel 2, and having its axis parallel thereto. The top-of thishood is relatively flat, with a sharply increasing curvature toward thesides thereof, terminating in vertical side walls. An auxiliaryreflector 8, in the form of a broad V with slightly concave legs isattached to the under side of the hood l along the top thereof. Saidreflector carriesbrackets 9 in which a substantially horizontal quartzmercury vapor arc lamp of the Cooper Hewitt type is supported,

said lamp being so positioned with respect to the reflecting hood I andthe reflector 8 that virtually all the light intercepted by saidreflecting surfaces is redirected upon the glasses 4 in the holders 3.Said reflector 8 has a series of ventilating openings ll along each sidethereof, which are staggered with respect to another series ofventilating openings l2 in the top of the hood I, so that hot air canescape from the top of said hood, while the ultraviolet radiations willbe trapped. The leadsto said lamp H) are conveniently brought in throughthe space between said reflector 8 and the hood 1. These leads areconnected to a suitable source of energy through suitable auxiliaryapparatus of conventional type. This auxiliary apparatus may be'placedin a container below the base I or in any other desirable place. Neitherthe auxiliary apparatus nor the location thereof forms any part of my'invention, however, and hence they will not be further described herein.Another auxiliary reflector I3 is aflixed to the base I along eitherside thereof near the base of the hood 1, each of these reflectors beingslightly concave and extending upwardly to the point where the curvatureof said hood 1 begins. Each of said reflectors l3 thus serves as acontinuation of the reflecting surface of said hood. A series ofventilating openings l4 near the bottom of said reflectors l3 arestaggered with respect to another series of openings IS in the sidewalls of said hood, thus admitting air without permitting the escape ofultraviolet radiations.

The back end of the hood I is closed ofi in any suitable manner, as by avertical wall a short distance behind the circular portion of thechannel 2, although an end wall having a surface of n such shape as toreflect more light on the glasses 4 may be used if desired. The frontend of said hood I terminates at the end of the straight legs of thechannel 2, and is closed by a plate l6 having openings I'I therein whichare but slightly larger than required for the passage therethrough ofthe holders 3 and glasses 4. As shown this plate is of metal, andcarries a glass insert l8 near the top thereof, this insert carrying anydesired legend; but if desired the entire plate may be made of glass,thereby attracting a greater degree of attention as a result of theradiations emitted therethrough. In either case the glass is opaque tothe ultraviolet radiations, and hence there is no danger to attendantsor observers from-escaping radiations. The channel 2 within the hood 1is made of such length that it is an even multiple of the diameter ofthe flanges 5, and enough of the holders 3 are placed .in said channelto occupy the entire channel within said hood, with one more of saidholders outside of said'hood. Thus whenever a holder 3 containing aglass 4 is pushed into an opening l'l until said holder and glasssubstantially fill the opening another holder 3 and glass 4 willsubstantially fill the other opening l'l, prerventing any appreciableescape of ultraviolet rathe reverse direction, however, said dog ismoved against a stop 2|, preventing further movement of said dog or saidholders, 'thus preventing a reversal in the direction of movement of theglasses 4 in the sterilizer, with its attendant use of only partlysterilized glasses.

In the use and operation of this sterilizing apparatus, assuming it tobe empty, a holder 3 is filled with a glass 4 and then pushed into theleft hand opening I! in the front plate Hi. This causes another holder 3to be ejected from the opposite opening I1. A glass is likewise placedin this holder, and the holder and glass then v pushed into theleft handopening, causing still another holder 3 to be ejected, these operationsbeing repeated until the first holder which was loaded appears in theright hand opening ll. Both of said openings are then substantiallyclosed by the respective glasses 4 and holders 3 positioned therein,with the result that no appreciable amount of ultraviolet can escapetherethrough. The mercury vapor lamp I0 is then started into operation,as for example by the wellknown inductive surge method, and allowed towarm up for aperiod of the order of ten minutes in order to allow thevapor pressure therein to increase to apoint where the radiationstherefrom will be rich in ultraviolet. A glass 4 is then placed in theempty holder 4 which is outside the hood 1, and said holder is thenpushed into the left hand opening l1, thus ejecting the glass and holderwhich have been only partially within the hood 1 during this lampwarming period. This glass 4 is not used, but is pushed back into theleft hand opening I! as soon as a sterilized glass is desired fordispensing purposes, causing a perfectly sterilized glass to be ejectedfrom the right hand opening. Thereafter a fresh glass is placed in theempty holder which is waiting whenever a sterile glass is desired, theinsertion of the fresh glass into the opening I! causing a sterile glassto be ejected as heretofore described. When the lamp is again startedafter any appreciable shutdown it is only necessary to await the warmingof the lamp, after which the operator proceeds as before, resterilizingthe first glass, and then using all thereafter for dispensing purposes.

As the holders 3 are-moved along the channel 2 the glasses 4 containedtherein receive a great deal of direct irradiation from the lamp I0. Dueto the shape of the reflecting hood Land of the reflectors 8 and [3these glasses moreover receive reflected radiations which reinforce thedirect radiations and reach portions of each glass which areinaccessible to direct radiations. Thus the entire inside of each glass4 and the outside thereof down to the holder 3 is continuously exposedto ultraviolet irradiation so long as the glass is within the hood 1.Twenty seconds of this irradiation has been found suflicient tocompletely sterilize a glass, hence an ample safety factor is provided,regardless of how dexterous the attendant may be, for obviously thenumber of glasses which may be used in twenty seconds is much less thanthe number contained within the hood I. As the holders 3 move along thechannel 2 there is a tendency, moreover, for them to turn, particularlyas they traverse the circular portion of said channel, with the resultthat different portions of the glasses 4 are subjected to the somewhatmore intense direct radiations from the lamp III. This further increasesthe factor of safety, since it increases the uniformity of irradiationand decreases the time necessary to sterilize the entire glass. Anyrinse water remaining on or in the glasses 4 will not prevent thesatisfactory sterilization of said glasses, since the water will besterilized as a result of the irradiation thereof, and water sosterilized is known to have bactericidal properties which will sterilizethe glass beneath. Moreover, a certain amount of the radiations willpass through this water, sterilizing the glass beneath by direct actionthereon. In some cases the glasses may contain aliquid, such as water,or one having either its transparency to the ultraviolet radiations orthe property of becoming bactericidal after irradiation, in which casethe inside of the container will likewise be rendered sterile in thesame manner as when some of the rinse water remains thereon. Any reversemovement of the holders 3, due to a lapse on the part of the operator,is of course prevented bysaid teeth and the walls of the channel 2, orthe teeth on another holder 3. At a desired point in said channel, suchas just after the holders have entered the returning straight leg,'asshown in Fig. 3, a rack 23 is inserted in the wall of said channel. Saidrack engages said teeth and causes a limited rotation, of the order of180*, of each holder 3 and the glass 4 contained thereby as it passessaid rack. While a single short rack has been shown it is-obvious thatothers may be added, or that a continuous rack may be added throughoutthe length of the channel 2 if a greater amount of turning is desired.

During operation of the sterilizer some of the visible radiations fromthe'mercury arc lamp I0 pass out through the glasses 4 which arepositioned in the openings ll, furnishing a spectacular appearance whichimmediately directs attention thereto. Thus the advertising value of thedevice is greatly enhanced by these illuminated glasses, while at thesame time these glasses serve the utilitarian purpose of preventing theescape of ultraviolet rays through the necessary entrance and exitopenings. The panel l8 with its illuminated legend also adds greatly tothe advertising value of the device without adding to the necessaryexpenditure of energy.

While I have described my novel method of sterilizing glasses byreference to a preferred structure it is to be understood that myinvention is not limited thereto, but that various omissions,substitutions and changes, within the scope of the appended claims, maybe made either in the steps of the process or in the structural detailswithout departing from the spirit thereof. I claim as my invention: 1.In apparatus for simultaneously irradiating both the interior and theexterior of containers, in combination, a source of ultraviolet light,means to support a container adjacent thereto,

and means to reflect radiations from saidsource to the interior of saidcontainer and to portions of the exterior thereof which are notsubjected to direct radiations from said source, said last mentionedmeans comprising a reflector having converging sides which extend alongeach side of a container on said supporting means.

2. In apparatus for irradiating containers, in combination, a tubularsource of ultraviolet light,

means to slidably support two rows of containers on a planesubstantially parallel to said light source with the open mouths'of saidcontainers facing in the general direction of said light source, meansto reflect radiations from said source to portionsof said containers notsubjected to direct radiations therefrom, means to move said containers,and means to rotate said containers with respect to said source as theyare moved.

3. In apparatus for irradiating containers, in combination, asubstantially horizontal tubular source of ultraviolet light, a basebelow said light source, a plurality of container holders mounted onsaid base for movement in a fixed endless i path, the major portion ofsaid path being constituted by two straight legs parallel to saidsource, and a housing for said lamp supported by said base, the interiorof said housing being adapted to reflect radiations from said source onportions of containers held by said 'holders which are not subjected todirect radiations from said source.

4. In apparatus for irradiating containers, in combination, asubstantially horizontal tubular source of ultraviolet light, a basebelow said light source, a plurality of container holders mounted onsaid base for movement in a fixed endless path, themajor portion of saidpath being constituted by two straight legs parallel to said source, ahousing for said lamp supported by said base, the interior of saidhousing being adapted to reflect radiations from said source on portionsof containers held by said holders which are not subjected to directradiations from said source, one endofsaid housing having openingstherein of substantially the same shape as said containers to permitingress and egress of said holders and the containers held thereby asthey move along the fixed path, the length of said path within saidhousing being an even multiple of the greatest diameter of said holders,whereby a container positioned in one of said'openings causes'anothercontainer to be automatically positioned in the, other of said openings,said containers forming an ultraviolet filter for said openings.

5. In apparatus for irradiating containers, in combination, asubstantially horizontal tubular source of ultraviolet light, a basebelow said light source, a plurality of container holders mounted onsaid base for movement in a fixed endless path,

the major portion of said path being'constituted on said base formovement in a fixed endless path, the major portion of said path beingconstituted by two straight legs parallel to said source, a housing forsaid lamp supported by said base, the interior of said'housing beingadapted to reflect radiations from said source on portions of containersheld by said holders which are not subjected to direct radiations fromsaid source,

means to move said holders along said path, and means to rotate saidholders as they are moved.

'7. The method of irradiating a container from a source of ultravioletlight which comprises subjecting portions of said containerto directradiations from said source, simultaneously reflecting radiations fromsaid source to the interior of said container and to portions of theexterior thereof which are not subjected to direct radiations, androtating said container with respect to said source to bring theindirectly irradiated portions of said container into the field ofdirect radiations from said source.

8. In apparatus for irradiating containers, in combination, a source ofultraviolet light, means to slidably support a plurality of containersalong which comprises moving the dishes through the eifective range of asterilizing radiation, and concomitantly rolling or turning the dishesto give 10 an effective exposure to the radiation.

LEROY J. BUTTOLPH.

